Liquid fuel burner



0d- 4, 1938 s. CHADWECK ET AL. 2,131,835

' LIQUID FUEL BURNER Filed March 27, 1957 Sheets-Sheet l I l I I INVENTOR-Y,

\ Q m 2. 29M? Oct. 4, 1938. L, s, w ET AL 2,131,835

LIQUID FUEL BURNER Filed March 27, 1957 s'; Sheets-Sheet 3 Patented Get. 4, 1d

LIQ FUEL BUR Rice 8. Chadwick, Shaker Heights, and Theodore E. Focke, Cleveland Heights, Ohio, assignors to jg Perfection Stove Company, Cleveland, Uhio, a

corporation of Ohio This invention is an improvement on the liquid fuel burner that forms a part of the heating apparatus described and claimed in Letters Patent No. 1,944,593, dated January 23, 1934.

i V The burner disclosed in that patent consists of a fuel basin in the nature of a pot having means for admitting primary air thereto and provided with a cover having an opening surrounded by a depending flange, and a combustion chamber having a bottom wall spaced a short distance above the cover of the fuel basin or pot and provided with a neck that extends into the opening oi the cover in spaced relation to the'aioresaid flange. The space between the pot cover and the bottom wall of the combustion chamber admits secondary air, and the neck serves to deflect said air downwardly into'the pot so that a turmoil is created therein when the burner is in operation, it being understood that means are provided for 9 'supplying liquld fuel to the pot.

The foregoing burner has proven to be efiicient and satisfactory when operating at medium and high fires, especially the latter; but when burning at low fire, combustion is not sumciently com- 5 plete to avoid the formation and accumulation 01' an undesirable amount of soot in the, fuel basin or fire pot.

The main object of the present invention is to produce a burner oi the above nature that operates satisfactorily and gives good combustion throughouta wide range from low to high fire.

Further objects of the invention are to provide, in a burner of the above nature, means for bettercontrolling the air supply so as to prevent 5 an overabundance of air from being admitted to the fire pot at low fire; and to provide means for maintaining within the fire pot a primary generating flame for vaporizing the liquid fuel when the burner is operating at high fire and 0 under which circumstances, in the presence of our improvement, the body of fuel in the bottom of the fire pot is so far removed and protected from the heat of the main flame that said heat has only a limited vaporizing efiect thereon.

5 Otherand more limited objects will appear as we proceed to describe our inventionin detail by reference to the accompanying drawings wherein like characters designate corresponding parts throughout the several views.

3 In the drawings, Fig, 1 is a central vertical section through the lower portion of a warm air furnace incorporating ourimproved burner; Fig. 2 is a similar sectional view of the burner, on a scale considerably enlarged over that of Fig. 1;

5 Fig. 3 is a sectional plan view of the burner;

Application March 2'7, 193?, Serial No. llBliAlM 11 Claims. (Cl.' 158--9ll)" tom'wall 5. Secured, as by bolts 6, to the underside of the wall ii, is the'peripheral portion of an annulus 1 whose inner edge is shown as flanged upwardly for stidening purposes. Attached to the annulus by fastening means ill and ii are the annular top wall it of a cylindrical burner vhousing it, and a ring-like member 15 whose inner edge is turned downwardly to provide a neck it.

The neck it is arranged in spaced relation to the downwardly flanged inner edge it of the annular top wall IQ of the burner bowl or fire not 20; and it will be observed that the periphery of said top wall is turned downwardly and flared slightly for application to the flared upper end of the peripheral wall of the fire pot, the parts being welded together, as indicated at 2i. The previously mentioned fastening means it are in the nature of double ended rivets having enlarged body portions 22, and they serve to support the fire pot with its top wall in properly spaced rela-' tion to the structure above. The before mentioned fastening means ii may consist of ordinary rivets.

The downturned outer edge of the top wall 89 of the fire pot is provided with a series of holes 23, while the peripheral wall of said pot has two circumferential rows of apertures, designated 2d and 25, respectively, that are located a suitable distance above the bottom wall 26 of the pot, and well above the maximum fuel level indicated by the dot and dash line a. When the burner is in operation, the oil level recedes to about the plane of the line b. Liquid fuel is supplied to the pot through a pipe 21, suitable means (not shown)-as, for example, azconstant level supply means-being employed for automatically shutting off the flow of fuel when the level reaches that indicated by the line a. In accordance with usual practice, a manually or otherwise operated valve (not shown) is included in the pipe 2] for controlling the supply of oil to the burner thereby to govern the height of the fire.

Projecting forwardly from the peripheral wall of the burner bowl or pct 20, is a sleeve til that surrounds the lighting and clean-out opening, designated generally by the reference numeral 3!. A cylindrical plug 32, having a handle 13, fits within and thus serves as a closure for the sleeve iii! and the same has a bayonet joint connection with the sleeve. said connection including an angular groove 34 that is formed in the plug and a projection 35 on the interior of the sleeve 31%.

Fitted within the lower end of the cylindrical wall l3 of the burner housing is a circular bottom wall 38 that is provided with a central opening fit over. which a deflector Ill is supported by brackets ll. Air is admitted to the interior of the burner housing through an air duct 42 having a branch 43 that registers with the opening 39; and the admission of air to said duct may be controlled by a damper 64 that is located adiacent the forward end of the duct where the latter projects through the front of the shell I and is shown as covered by a perforated shield 45. The air admitted through the duct 42 finds its way to the interior of the bowl or pct 20 through the previously mentioned perforations 24 and 25, through the holes 28, and through the passage designated A between the ring-like member if: and the top wall IQ of the fire pot, the air entering through said pwsage being deflected downwardly into the pot by the neck l8.

Air at atmospheric pressure may be admitted to the duct 42, as intended in the construction illustrated; or in accordance with a very common practice, a forced draft may be supplied by communicatively connecting the discharge of a fan or blower (not shown) to the duct 42.

The previously mentioned sleeve 30 extends through an opening in the cylindrical wall l3 into the interior of a funnel-like structure 48 that opens at its larger end through the front of the shell I and has its smaller end engaged with the wall l3 about the sleeve 30. A collar 41 closes the joint between the sleeve and wall it.

The burner proper,,as thus far described, is essentially the same as that shown in the above mentioned patent. l'I'he present invention provides means for shielding the lower interior portion of the fire pot from the air entering through the passage A and, in the form illustrated in Figs. 1 to 4, the same consists of an inverted frusto-conical shield -50, whose upper edge is welded or otherwise secured to the flanged inner edge 18 of the top wall I9 of the fire pot, andwhose lower portion is curved inwardly and upwardly to form a throat 52. with this construction, the air entering through the passage A descends to about the lowerend of the shield 50 and is then deflected inwardlyand upwardly and thus prevented from disturbing the conditions within the firepot that are conducive to proper combustion when the burner is operating at low fire. When the burner is so operating, sufilcient air enters through the apertures 24 and 25 to produce satisfactory combustion reasonably free from carbon, and the flame rises through the throat 52 into the combustion chamber 4, the air supplied through the passage A rising with the products into said chamber. Air willalso enter the fire pot through the holes 23 adjacent the top thereof and this air will commingle with the vapors that rise into the space between the shield 50 and the peripheral wail of the pot and produce an inflammable mixture that will ignite and join the other products of combustion rising through the throat 52.

When the burner is operating at medium and high flres, thedemand for air for the support of menses combustion increases and only enough air enters through the apertures 24 and 25 to constitute the so-called primary air supply which, mixing with the vapors rising from the body of fuel in the bottom of the pot, forms a gas that is too rich to burn readily and this gas rises through the throat 52 where it is immediately joined by the secondary air that sweeps over the top wall of the fire pot through the passage A. So augmented, the gas becomes combustible and ignites and the flame is projected through the neck l8 into the combustion chamber 4. Under these conditions, the main flame is so far removed from the body of fuel in the bottom'oi the fire pot that heat from said flame is insufficient to generate the required amount of vapor, but added to the heat from this source is that of a primary generating flame that occurs between the shield 50 and the peripheral wall of the'burner. This primary generating flame results from the mixing of a part of the vapors that rise within the burner bowl or not and are trapped behind the shield 50 and are Joined by air entering through the holes 23. The air descending reaches a point where it properly balances with the vapors to create a combustible mixture that burns at about the zone designated by the arrow X in Fig. 2.

In order to make certain that a part of the I air entering through the passage A descends. under all conditions of operation, in close proximity to and throughout. the vertical extent of the shield 50, for the two-fold purpose of better distributing the air and preventing undue heating of the shield, a baffle 55, shown in Fig. 4, may be included. This baiile consists of an inverted frusto-conical plate whose larger end is flared.

outwardly and mounted on the fastening means or rivets li and clamped between the body portions 22 thereof and washers 56 that are applied to the stems of the rivets. The baffle 55 divides the quantity of air entering through the passage A and deflects a part of it downwardly to the lower end of the shield where it escapes about the corresponding end of the baffle and isv deflected upwardly by the reentrant portion of the shield 50.

In the modification of the invention shown in Fig. 5, the shield 50 is 'frusto-conical throughout its length and extends deeper into the pot than does the shield 50 of the first described form. The performanceof this burner is substantially the same and as satisfactory from a practical standpoint as that of the former construction although the control of the secondary air may not be as uniform throughout the full range of operation. Also, with respect to different size burners as the diameter of the pot increases in relation to the diameter-of the opening in the top wall, the shield may become less tapered and finally assume cylindrical form.

Such changes are so obvious that illustration V 2,131,835 2. A burner comprising, in combination, a fuel basin having means spaced a substantial distance below its top for admitting air to the basin, a combustion chamber including a wall spaced above the basin and provided with a neck that projects into the basin in spaced relation to the l'lln thereof so that air that enters through the space between said wall and rim is deflected downwardly, and a shield of substantial depth depending from the rim of the basin and spaced inwardly from the peripheral wall of the latter, there being means in addition to the above mentioned means for admitting air to the space between said wall and the shield at an elevation adjacent the top of said space.

3. A burner comprising, in combination, a fire pot having means for admitting air thereto, a

cover for said pot provided with an opening, the material of said coverabout said opening being turned downwardly to form a flange, a combustion chamber above the pot having a bottom wall 7 spaced from said cover and provided with a neck thatprojects into the opening of the cover in "spaced relation to the aforesaid flange, and a shield having its upper end connected to said flange and depending a material distance into the pot, the pot having means for admitting air to the space between its peripheral wall and the shield immediately below its cover.

4. A burnercomprising, in combination, a fuel basin having means spaced a substantial distance below its top for admitting air to the basin, a combustion chamber above the basin having a neck that projects 'into' the basin in 5 spaced relation to the rim thereof, and a frustoconical shield having its upper edge secured .to I the rim of the basin and depending a material" distance into the basin, there being means in addition to the above mentioned means for'adrim.

pot having, means for' admittingair thereto, a

tom wall spaced from the cover and provided with a neck that projects into the opening of thecover gm. spaced relationto the edge] thereof; and a frustoj-conicalyshield having. itslupp'er edge secured to the cove'nraboutj saidopening', the shield depending ama rial distance "into the-fire pct,

"thepotinc'luding v diately below its c ver,

bustion chamberjand the basin serving as a passage for secondary air, and ashield of substan air to the basin immediately below its 5. A burner comprising, in combinatiomia fire.v

means: radmitting lmmej V the opening therein, the shield depending a material distance into the fire pot, the pot including 1 means for admitting air immediately below its cover, an inverted frusto-conical baiiie projecting a [,irito the shield in spaced relation thereto and combustion chamber spaced a relatively short. distance above ,the, basin and provided, with an opening through vwhich l the, basin communicates with said chamber, the space between the "comtial depth depending from the rim of the basin and spaced inwardly from the peripheral wall of the latter. V

7. A burner comprising, in combination, a fuel pot having means for admitting air to the bottom portion thereof and incorporating an annular top, a combustion chamber having a wall spaced above the pot and provided with an opening through which the pot communicates with said chamber, the space between said wall and the pot serving as a passage for secondary air, and a shield attached to and depending from the inner edge of said annular top, the fuel pot having air admitting openings adjacent its top.

8. A burner comprising, in combination, a fire pot having means for admitting air to the bottom portion thereof, a cover for said pot provided with an opening, a combustion chamber above the pot having a bottom wall spaced from the cover and provided with an opening in operative relation to the rim thereof so that air may enter through the space between said chamber and rim, and a shield of substantial depth depending from the rim of the basin and spaced inwardly from the peripheral wall of the latter, there being means for admitting air to the space between said wall andtheshield at top of said space.

'10. A burner comprising, in combination, a fuel basin having means for admitting air thereto, a combustion chamber above the basin an elevation adjacent the in spaced relation to the rim thereof so that airmay enter through the space between said chamberand rim, and a shield depending from the trim of the basin and spaced inwardly from the peripheral wall of the latter, the lower end of the I shield being turned inwardly and upwardly. l1. A'burner comprising, in combination, a fire pot having means for admitting air thereto,'a cover for said pot provided with an opening, a xcombustion chamber above the pot in spaced re- I latidn to the cover thereof, a frusto-conical shield having its upper edge secured to the cover about having its upper end flared outwardly within the space between the combustion chamber and the cover of the basin, and means supporting the bailie.

, LEE S. CHADWICK.

THEODORE B. E. 

